The research proposed here has three main goals. The first is the continuing study of the normal development of visual sensitivity, binocular function and oculomotor control in infants and children of both sexes. The second is the delineation of the correlative changes in the several meaures of sensitivity and oculomotor function in order to model the development of the visual system and to relate this model to the development of the underlying neuronal mechanisms. The third is the production of computer-automated procedures for testing visual function in the both the laboratory and the clinic and computerized database management of research data and subject pool. The detailed projects include: 1. Studies of the relative rates of development of the binocular functions of stereoacuity, fusion and rivalry, and brightness summation of the pupillary response. Modeling the developing binocular system in conjunction with current knowlege of neuronal function. 2. Measures of the normal development of binocular oculomotor control of eye alignment and accommodation for clear single binocular vision, and the correlation of these measures with the development of binocular visual function. 3. Quantification of development in sensitivity to changes in edge orientation. 4. Studies of variation in vernier acuity as a function of meridional variation in edge orientation. 5. Measurement of the course of development of acuity in the periphery of the retina. 6. Establishment of a computerized database and subject pool. 7. Automation of visual testing procedures to increase efficiency and clinical usefulness.